Hi team,
I'm study c6678 pcie userguide. And find below information:
” There are bandwidth implications of using an external DMA. If the PCIe core has been programmed to establish a link in the PCIe 2.5 Gbps rate, then the DMA controller that drives the PCIESS slave port must be able to write/read data at about 85% of 2 Gbps bandwidth per PCIe link. For a PCIe link speed of 5.0 Gbps, the DMA controller must be able to provide bandwidth of about 85% of 4 Gbps per PCIe link. In addition, the master port on PCIe port can issue read/write accesses that have been initiated by a remote PCI Express device. The interconnect fabric should provide sufficient capacity to serve 85% of 2 Gbps (4 Gbps in Gen2 mode) per PCIe link in each direction.”
My qustions:
1, Does this means EDMA must carry data more than 2 Gbs bandwidth at least. If EDMA run slow will cause some error?
2,If customer hope to use lower bandwidth, how to do it?
thanks!
BR,
Denny
